A lot of website homepages don't do this very well because the creator is too close to the detailed work of building it and can't see the forest for the trees. They have a lot to say about the features but often neglect to have a screenshot/video above the fold that shows visitors the UB. They also tend to put 100% of the webtool behind a login or paywall instead of letting casual users dive in and play around to discover the value.